SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '' 
    OR cscart_product_descriptions.short_description IS NULL, 
    cscart_product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    95708, 95709, 95710, 95711, 95712, 95713, 
    95714, 95715, 95716, 95717, 95718, 
    95719, 95720, 95721, 95722, 95723, 
    95724, 95725, 95726, 95727, 95728, 
    95729, 95730, 95731, 95732, 95733, 
    95734, 95735, 96122, 96124
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00080

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "13.52"
    },
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 30,
      "rows_produced_per_join": 30,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "10.52",
        "eval_cost": "3.00",
        "prefix_cost": "13.52",
        "data_read_per_join": "114K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (95708,95709,95710,95711,95712,95713,95714,95715,95716,95717,95718,95719,95720,95721,95722,95723,95724,95725,95726,95727,95728,95729,95730,95731,95732,95733,95734,95735,96122,96124)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
95708
95709
95710
95711
95712
95713
95714
95715
95716
95717
95718
95719
95720
95721
95722
95723
95724
95725
95726
95727
95728
95729
95730
95731
95732
95733
95734
95735
96122
96124